Sharpening device

ABSTRACT

Apparatus for sharpening the shaft mounted blades of a planarjointer including a base member for mounting onto the planarjointer table over the blades thereof and positioning means mounted onto the base member for positioning the base member and a blade of the planar-jointer for sharpening.

limited States Patent 1191 lBonke Aug. 13, 1974 [54] SHARPENING DEVICE2,729,923 l/l956 Durst .Q 51/249 Y 2,792,036 5/1957 B ttk 51/249 [76]inventor: Henry F" 2605 3,354,589 11/1967 Pt i stufa et al.. 51/249Colorado Springs, Colo- 80904 3,691,702 9/1972 Smith 51/249 [22] Filed:Nov. 17, 1972 Przmary ExammerOthell M. Simpson PP 307,578 Attorney,Agent, or Firm-Pravel, Wilson & Matthews 52 us. 01. 51/249 [57] ABSTRACT[5 l Int. Cl B24b 19/00 Apparatus for Sharpening the shaft mountedblades of [58] Field of Search 51/246, 247, 249 a planar-jointerincluding a base member for mounting onto the planar-jointer table overthe blades thereof [56] References Cited and positioning means mountedonto the base member UNITED STATES PATENTS for positioning the basemember and a blade of the 900,284 10/1908 Kahle 51 /249 planar'lomer forSharpening 2,664,641 l/1954 Parnet 51/216 H 8 Claims, 5 Drawing Figures5 2 20 Z0 23 /Z& i 1 S 246 t l l 3 //Q /0 "a P A; 7 3 /4a /5 m, 0

SHARPENING DEVICE BACKGROUND OF THE INVENTION The field of thisinvention is sharpening devices.

A planer-jointer is well-known in the field of woodworking for cuttingor planing wood surfaces. A typical planer-jointer has a shaft-mountedrotating cutting head having blades extending outwardly therefrom.Generally, the blades of a planer-jointer are removed from the cuttinghead for sharpening and thereafter replaced. The replacing of the bladesin the cutting head is very tedious since the cutting height of suchblades is critical.

Various attempts have been made to devise an apparatus for sharpeningplaner-jointer blades without removing them from the cutting head. Forexample, US. Pat. No. 2,729,923, issued to Durst, disclosed a sharpeningdevice which included a base plate and a carrier plate for mounting overthe planer-jointer table. In Durst, the carrier plate is pivoted to aposition over the open area of the planer-jointer table and' rails areprovided for guiding a grinder in a transverse movement along a blade,which is held in position by an arm attached to a shaft pulley and by ablade indexing block.

SUMMARY OF THE INVENTION It is an object of this invention to provide anew and improved apparatus for sharpening in place the blades of aplaner-jointer. The sharpening apparatus of this invention includes abase member having an opening therein such that the base member may beplaced on a planer-jointer table with the base member opening alignedwith the open space between the-sections of the planer-jointer table.Base member positioning means is mounted on the base member for engaginga section of the planer-jointer table in order to position the basemember thereon. The blade of the p'laner-jointer to be sharpened ispositioned by a stud extending outwardly from the base member intoengagement with the underside of the blade and, guide members aremounted onto the base member on opposite sides of the base memberopening in order to, guide a grinder along the planerjointer blade.

As an additional feature, a locking arm is clamped onto theplaner-jointer shaft and rests against the table in order to secure theshaft against movement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional view inelevation illustrating the sharpening device of the preferred embodimentof this invention in position on the table of the planer-jointer;

FIG. 2 is a top view taken along line 2 2 of FIG. 1 of the sharpeningdevice;

FIG. 3 is a bottom view taken along line 3 3 of FIG. 1 of the sharpeningdevice with the position of the planer-jointer table being illustratedschematically;

FIG. 4 is a sectional view taken along line 4 4 of FIG. 2 illustratingvarious positioning elements for the sharpening apparatus; and

FIG. 5 is a side view of the shaft locking arm of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, theletter S generallydesignates a sharpening device for sharpening a planerjointer (or jointer) P without having to remove the 0 nated as T. Thetable T includes a front section 12 and l a rear section 14 separated byopen area 0. The open area or space between the front table section 12and the rear table section 14 is defined by front'table section insidewall 12a and rear table section inside wall The cutting head 11 ismounted onto shaft 15 for rotation therewith by any suitable means suchas keys (not shown). The cutting blades 10 are mounted in substantiallyradially directed slots 1 la in the cutting head 11 such that the blades10 extend radially outwardly from the periphery 11b of the cutting head.The cutting blades are held in place by set screws (not shown) or othersuitable means. If the blades 10 must be removed in order to besharpened, the blades must be replaced in the cutting head 11' such thateach blade cuts at exactly the same level and angle, which requires agreat deal of tedious effort. The shaft 15 is mounted for rotation ontosome type of frame (not shown) by any suitable means such asbearings 16aand 16b. A pulley 17 is mounted for rotation with the shaft 15 and isdriven by a motor and belt combination (not shown). The height of thefront table section 12 of the planer-jointer P is adjustable "such thatthe thickness of the wood to be removed by planing is adjustable.Generally, the cutting point 10a of the cutting blade is adjusted or setto an elevation (at the highest point) substantially equal totheelevation of the top 14b of the rear table section 14 such that thethickness of material being planed by the planer-jointer P is measuredby the difference in height between the top 1412 of the rear tablesection and top '12b of the front table section.

The sharpening device S of the preferred embodiment of this inventionincludes a flat, base member or plate 20 having an oblong opening 21extending transversely thereof. The base member 20 may be a plastic orother suitable material, preferably light weight and translucent. Sideblocks 23 are mounted onto each of the four 'corners 20a'of the basemember 20. Each side block 23 has a slot 23a therein extendingtransversely 26 to the longitudinal axis 24 of the planer-jointer tableT. Screws 25 extend through the slot 23a and into threaded engagementwith underside 20b of the slot 23a and into threaded engagement withunderside 20b of the base member 20. Each of the side blocks 23 aresufficiently thick to extend down over the sides of the front and reartable sections 12 and 14, respectively. For example, side blocks 23extend downwardly over the top 12b of the front table section 12 and arepositioned for engagement against side walls and 12d of the front tablesection 12. By adjusting the side blocks until such blocks abut againstthe sides such as 120 and 12d of the table sections 12 and 14, the basemember 20 can be secured against transverse movement 26.

As previously mentioned, the front table section 12 is adjustable inheight with respect to the height of the rear table section 14; and, inutilizing the sharpening apparatus S of this invention, it is desirablethat the front table section 12 be slightly lower in elevation or heightthan the rear table section 14. In order to compensate for suchdifference in height, stabilizing plates 27 and 28 are mounted ontounderside 20b of the base member 20 by any suitable means such asgluing. The thickness of the stabilizing members or plates 27 and 28 issufficient to compensate for the desired height difference between fronttable section 12 and rear table section 14 of the planer-jointer P.Thus, when the base member 20 is mounted over the front and rear tablesections 12 and.14, the stabilizing plates 27 and 28 rest upon fronttable section top 12b such that top surface 20c of the base member 20 issubstantially level.

Stabilizer plate 27 includes a recessed area 27a. A metal stud or plate30 is mounted in recess 27a and includes a portion 30a which extendsoutwardly into the area of base member opening 21 in order to engageunderside b of a cutting blade 10 to thereby position a cutting blade 10at the desired angle or bevel for sharpening. The edge 30b of the plate30. is beveled such that the underside 10b of the blade 10 beingsharpened can rest thereagainst at an angle. In this manner, the cuttingsurface 10c of the blade 10 is held at substantially a level orhorizontal position for sharpening. The blade positioning plate 30 isadjustably mounted within the recess 27a in the stabilizer plate 27.Oblong slots 31 and 32 are machined into the base member and intostabilizer plate 27 and adjusting screws 33 and 34 extend through theoblong slots 31 and 32 into threaded engagement with the plate 30. Thus,by loosening the screws 33 and 34, the position of the base plate withrespect to the blade 10 can be adjusted as desired.

Base member positioning elements 35 and 36 are also mounted in recess27a in the stabilizer plate 27. The L- shaped elements 35 and 36 includevertical portions 35a and 36a, respectively, which extend downwardly inorder to be placed against front table section inside wall 12a. Thepositioner elements 35 and 36 are adjustably mounted within the recess27a. Oblong slots 37 and 38 are machined into the base member 20 andinto the stabilizer plate 27 such that adjustment screws 39 and 40 canbe mounted in slots 37 and 38, respectively, and extend into threadedengagement with the elements 35 and 36. The function of the L-shapedelements 35 and 36 is to position the base member 20 such that the bladepositioning plate 30 and base member opening 21 are aligned properlywith respect to the cutting head 11 and the blade 10 to be sharpened.

A locking arm 42 is attached to end 15a of the shaft 15 and extends ontorear table section top 14b in order to secure the shaft 15 againstcounter-clockwise rotation (HO; 1) while the blade 10 is beingsharpened. The locking arm 42 includes an end portion forming a collar42a which extends about the shaft 15a with a bushing or sleeve 43positioned therebetween. The

bushing or sleeve can be polytetrafluoroethylene orother suitablematerial which will protect the shaft 15a. The collar end portion 42aextends about the bushing 43 and includes a clamping portion 42b havinga clamping nut 42c extending therethrough into threaded engagement withthe main portion 42d of the locking arm 42. Thus, the collar end portion42a and bushing 43 are mounted over the shaft end 15a and the clampin'gnut 42c is screwed tightly to draw the clamping end shaft end 15a. Themain body portion 42d of the arm is L-shaped such that a portion 42eextends inwardly into a position of engagement with rear section tabletop 14b. Actually, the portion 42e of the locking arm includes avertical connecting portion 42f and a horizontal tip 42g which actuallyis positioned to engage the rear section table top 14b.

A grinder G is used to actually grind the blade 10 being held in placeby the blade positioning plate 30 and shaft locking arm 42, whichcooperate to prevent rotation of shaft 15 (and thus blade 10) in eitherclockwise or counter-clockwise direction (see FIG. 1). The grinder G isof typical grinder construction and includes a motor 45 having acircular housing 45a mounted therewith, the circular housing including abottom rim 45b. The motor shaft 45c extends downwardly from the motor 45and a grinding head 45d is mounted thereon. The housing 45a serves toprotect the user from flying particles from the grinding operation.Guide bars 46 and 47 are provided on opposite sides of the opening 21 inthe base member 20 in order to provide a guide path for the grinder G.The guide bar 46 has oblong slots 46a and 46b and, a plurality of screwholes such as 480 and 48b are machined in the base member 20. A screw 49extends through each of the oblong slots 46a in the guide bar 46 andinto one of the plurality of holes 4811 and 48b. In this manner, therelative position of the guide bar 46 can be adjusted when the screws 49are in one of the holes 4811 and 48b and, the position of the guide bar46 can be even further varied by threadedly mounting the screws 49 inany of the other holes 480 and 48b.

Similarly, the guide bar 47 has oblong slots 47a and 47b therein andsets of aligned holes 500 and 50b are located in the base member 20.Screws 51 extend through the slots 47a and 47b and into the holes 50aand 50b. Thus the relative position of the guide bar 47 with respect tooblong base member opening 21 can be adjusted by using the screws 51and/or any of the holes 50a and 50b. Guide bars 46 and 47 provide insiderails or edges 46c and 47c for receiving and guiding grinder housing rim45b. in this manner, various sizes of grinders G may be utilized tosharpen the planer-jointer blades 10. No matter what the size of thegrinder G is, the guide bars 46 and 47 are adjusted on the base member20 such that grinder head 45d is positioned therebetween to engage andmove along the blade 10 being sharpened.

In operation and use of the sharpening apparatus S to sharpen the blades10 of a planer-jointer P, the blades 10 are first cleaned in order toremove any dirt, oil or grime thereon. The sharpening apparatus S isthen placed onto the front and rear table sections 12 and 14. The fronttable section 12 is lowered until the top surface l2b thereof isapproximately one-quarter of an inch lower in elevation than the topsurface 14b of the rear table section 14. The base member 20 with thestabilizing plates 27 and 28 engaging top front table section surface12b is then tapped or otherwise maneuvered until the top surface 200 issubstantially horizontal or level. The side blocks 23 are then adjustedto engage the sides such as 12c and 12d of the front table section12.This is accomplished by loosening screws 25 and moving the blocks 23into engagement with the sides of the table section and thereafterscrewing tight the screws 25 again. The base member 20 is then pulled orpushed away from rear table section 14 until the ver- The bladepositioning plate 30 is then positioned to engage underside b of one ofthe bladeslO in order to properly position cutting surface or edge We ofthe blade and prevent rotation of the blade 10 in a clockwise directionunder the force of the grinder G (FIG. 1). The objective is to positionthe blade 10 to be sharpened such that the cutting surface 10c issubstantially horizontal in order to prevent unnecessary cutting or ruinthe bevel of the cutting blade 10. The blade positioning plate 30 isadjusted in position by loosening screws 33 and 34 such that the screwsare free to move within oblong slots 32 and 31, respectively.Thereafter, the screws 33 and 34 are tightened to secure the plate 30and thus the balde 10 being sharpened, as illustrated in FIG. 1, in thedesired position. The locking arm 42 is then mounted over shaft endportion a by mounting the bushing 43 and collar end portion 42a over theshaft end 15a. Clamping screw 42c is then tightened to tighten thecollar end portion 42a about the shaft end portion 15a. The locking arm42 is positioned such that horizontal tip 42g is resting onto rearsection top table surface 14b prior to the collar end portion 42a beinglocked or clamped about the shaft end'portion 15a. In this manner, theshaft 15 islocked against rotational movement in any direction under theforce of the grinder G. The guide bars 46 and 47 are positioned suchthat the distance therebetween is substantially equal to the diameter orwidth of the grinder housing edge 45b so that the grinder G can be movedacross the blade 10 to be sharpened smoothly. The actual height of theblade 10 being sharpened is determined by the position of the grinderhead 45d. Of course, it is desirable to sharpen all three of theseblades 10 without changing any of the adjustments on either thesharpening apparatus or the grinder G such that the cutting heights ofthe blades 10 are identical.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

For example, it should be understood that the various elements such asbase member 20, which has been disclosed as being plastic, or the metalplate 30 can be made of other suitable materials than those discussed.Further, it should be understood that the sharpening apparatus S may beused'with various types of grinders other than the grinder G disclosedand that the sharpening apparatus S may be adapted for use on varioussizes of planer-jointers P.

I claim:

1. Apparatus for sharpening a planer-jointer having a shaft with bladesmounted thereon positioned inan open area in a planer-jointer table,said apparatus being adapted for use with planer-jointers of differentsizes and comprising:

a base member having an opening therein, said base member adapted formounting on said table such that said base member opening substantiallyaligns with said open area of said planer-jointer table; base memberpositioner means for engaging said table at said open area forpositioning said base member on said table; said base member positionermeans including:

horizontal members extending from said base member parallel to the topof the planer-jointer 'table; and

vertical portions mounted with said horizontal members for engaging thetable at its open area;

blade positioner means mounted on said base member for adjustableextension parallel to the top of the table to engage a blade andposition the blade;

guide members mounted on said base member about said base member openingfor guiding a grinder along a blade;

base member positioner adjusting means for adjusting the extension ofsaid base member positioning means from said base member to control theposition of said base member on the table; and

blade positioner adjusting means for extending and retracting said bladepositioner means from said base member, whereby said base member and theblade are positioned independently to permit positioning of saidapparatus on planer-jointers of different sizes and the blades of theplaner-jointer are sharpened without removal. 2. The structure set forthin claim 1 including: shaft lock means attached to said shaft andextending to said table for locking said shaft against rotation.

3. The structure set forth in claim 1, including:

side blocks adjustably mounted on each corner of said base member; and

adjusting means for adjusting the position of each of said blocks withrespect to said base member and said table to position said base memberon said table and secure said base member.

4. The structure set forth in claim 1, wherein:

said base member is of unitary construction.

5. The structure set forth in claim 2, wherein said shaft lock meansincludes:

a collar portion for mounting about said shaft; and

clamping means for clamping said collar portion onto said shaft.

6. The structure set forth in claim 5, including:

a bushing mounted within said collar portion for preventing damage tosaid shaft.

7. The structure set forth in claim 2, wherein:

said blade positioner and said shaft lock means cooperate to preventmovement of said blade being sharpened in any direction.

8. The structure set forth in claim 1, including:

means mounted on said base member for adjusting the position of saidguide members on said base member.

1. Apparatus for sharpening a planer-jointer having a shaft with bladesmounted thereon positioned in an open area in a planerjointer table,said apparatus being adapted for use with planerjointers of differentsizes and comprising: a base member having an opening therein, said basemember adapted for mounting on said table such that said base memberopening substantially aligns with said open area of said planer-jointertable; base member positioner means for engaging said table at said openarea for positioning said base member on said table; said base memberpositioner means including: horizontal members extending from said basemember parallel to the top of the planer-jointer table; and verticalportions mounted with said horizontal members for engaging the table atits open area; blade positioner means mounted on said base member foradjustable extension parallel to the top of the table to engage a bladeand position the blade; guide members mounted on said base member aboutsaid base member opening for guiding a grinder along a blade; basemember positioner adjusting means for adjusting the extension of saidbase member positioning means from said base member to control theposition of said base member on the table; and blade positioneradjusting means for extending and retracting said blade positioner meansfrom said base member, whereby said base member and the blade arepositioned independently to permit positioning of said apparatus onplaner-jointers of different sizes and the blades of the planer-jointerare sharpened without removal.
 2. The structure set forth in claim 1including: shaft lock means attached to said shaft and extending to saidtable for locking said shaft against rotation.
 3. The structure setforth in claim 1, including: side blocks adjustably mounted on eachcorner of said base member; and adjusting means for adjusting theposition of each of said blocks with respect to said base member andsaid table to position said base member on said table and secure saidbase member.
 4. The structure set forth in claim 1, wherein: said basemember is of unitary construction.
 5. The structure set forth in claim2, wherein said shaft lock means includes: a collar portion for mountingabout said shaft; and clamping means for clamping said collar portiononto said shaft.
 6. The structure set forth in claim 5, including: abushing mounted within said collar portion for preventing damage to saidshaft.
 7. The structure set forth in claim 2, wherein: said bladepositioner and said shaft lock means cooperate to prevent movement ofsaid blade being sharpened in any direction.
 8. The structure set forthin claim 1, including: means mounted on said base member for adjustingthe position of said guide members on said base member.